There is a conventionally proposed principle of a compressing mechanism which includes a rotary cylinder having a groove, and a piston slidable within the groove, so that the rotary cylinder is rotated in accordance with the movement of the piston to perform suction and compression strokes (for example, see German Patent No. 863,751 and British Patent No. 430,830).
The conventionally proposed principle of the compressing mechanism will be described below with reference to FIG. 26.
The compressing mechanism is comprised of a rotary cylinder 101 having a groove 100, and a piston 102 which is slidable within the groove 100. The rotary cylinder 101 is provided for rotation about a point A, and the piston 102 is rotated about a point B.
The movements of the piston and the cylinder will be described as for a case where the rotational radius of the piston 102 is equal to the distance between the center A of rotation of the rotary cylinder 101 and the center B of rotation of the piston 102.
When the rotational radius of the piston 102 is larger, or smaller than the distance between the rotational center A of the rotatable cylinder 101 and the rotational center B of the piston 102, different movements are performed. The description of these different movements is omitted herein.
A broken line C in FIG. 26 indicate a locus for the piston 102.
FIGS. 26a to 26i show states in which the piston 102 has been rotated through every 90 degree.
First, the movement of the piston 102 will be described below. FIG. 26a shows the state in which the piston lies immediately above the rotational center B. FIG. 26b shows the state in which the piston 102 has been rotated through 90 degree in a counterclockwise direction from the state shown in FIG. 26a. FIG. 26c shows the state in which the piston 102 has been rotated through 180 degree in the counterclockwise direction from the state shown in FIG. 26a. FIG. 26d shows the state in which the piston 102 has been further rotated through 270 degree in the counterclockwise direction from the state shown in FIG. 26a. FIG. 26e shows the state in which the piston 102 has been rotated through 360 degree in the counterclockwise direction from the state shown in FIG. 26a and has been returned to the state shown in FIG. 26a.
The movement of the rotary cylinder 102 will be described below. In the state shown in FIG. 26a, the rotary cylinder 101 is located, so that the groove 100 is located vertically. When the piston 102 is moved through 90 degree in the counterclockwise direction from this state, the rotary cylinder 101 is rotated through 45 degree in the counter-clockwise direction, as shown in FIG. 26b and hence, the groove 100 is likewise brought into a state in which it is inclined at 45 degree When the piston 102 is rotated through 180 degree in the counterclockwise direction from the state shown in FIG. 26a, the rotary cylinder 101 is rotated through 90 degree in the counterclockwise direction, as shown in FIG. 26c and hence, the groove 100 is likewise brought into a state in which it is inclined at 90 degree.
In this way, the rotary cylinder 101 is rotated in the same direction with the rotation of the piston 102, but while the piston 102 is rotated through 360 degree, the rotary cylinder 101 is rotated through 180 degree.
The change in volume of the groove 100 defining the compressing space will be described below.
In the state shown in FIG. 26a, the piston 102 lies at one end in the groove 100 and hence, only one space 100 exists. This space 100 is called a first space 100a herein. In the state shown in FIG. 26b, the first space 100a is narrower, but a second space 100b is produced on the opposite side of the piston 102. In the state shown in FIG. 26c, the first space 100a is as small as half of the space in the state shown in FIG. 26a, but a second space 100b of the same size as the first space 100a is defined on the opposite side of the piston 102. The first space 100a is zero in volume in the state shown in FIG. 26e in which the piston 102 has been rotated through 360 degree.
In this way, the two spaces 100a and 100b are defined by the piston 102 and repeatedly varied in volume from the minimum to the maximum and from the maximum to the minimum, whenever the piston 102 is rotated through 360 degree.
Therefore, the spaces defining the compressing chambers perform the compression and suction strokes by the rotation of the piston 102 through 720 degree.
It is a main object of the present invention to utilize the above-described compressing principle in the hermetic compressor.
The above-described compressing principle suffers from the following problem: When the piston 102 is at the center A of rotation of the rotary cylinder 101, the direction of a force provided by the rotational force of the piston 102 is the same as the direction of the groove 100 and hence, this force does not serve a force for rotating the rotary cylinder 101. Therefore, when the piston 102 is at the center A of rotation of the rotary cylinder 101, the above-described movement is actually continuously not performed, if the rotational force is not applied to the rotary cylinder 101.
A continuous movement is realized by using a plurality of compressing mechanisms synchronized with each other with different phases. More specifically, by using a plurality of compressing mechanisms synchronized with each other with different phases, the rotational force of one of the rotatable cylinders can be applied to the other rotatable cylinder. Therefore, even if either one of the rotatable cylinders is brought into a state in which it does not receive the rotational force from the piston, the other rotatable cylinder applies the rotational force to the one rotatable cylinder and hence, the rotation can be continuously maintained.
However, when the plurality of compressing mechanisms with different phases are used, the compressing strokes in the compressing chambers in the compressing mechanisms are different from each other. For this reason, a partition plate for isolating the adjacent compressing mechanisms is required. To ensure a smooth rotation, the synchronization of the plurality of compressing mechanisms must be made reliable.
Accordingly, it is an object of the present invention to provide a hermetic compressor using a plurality of compressing mechanisms with different phases, wherein the synchronization of the plurality of compressing mechanisms can be made reliable.
It is another object of the present invention to provide a hermetic compressor, wherein the reliable synchronization of the compressing mechanisms can be realized by a particular structure capable of being industrially produced.
It is a further object of the present invention to provide a hermetic compressor, wherein a high suction efficiency can be realized.
It is a yet further object of the present invention to provide a hermetic compressor, wherein a high compressing efficiency can be realized.
Further, it is an object of the present invention to provide a hermetic compressor, wherein a non-circular piston is employed, and the area of contact between a rotary cylinder and the piston is increased to enhance the sealability and to enhance the sucking and compressing efficiencies.